To the Users of the EF300mm f/2.8L IS II USM, EF400mm f/2.8L IS II USM, EF500mm f/4L IS II USM, and EF600mm f/4L IS II USM Interchangeable Lenses for Canon Digital SLR Cameras

Thank you for using Canon products.

Canon has released a firmware update for EF300mm f/2.8L IS II USM, EF400mm F2.8L IS II USM, EF500mm f/4L IS II USM and EF600mm f/4L IS II USM lenses. This firmware update will be performed by Canon Service Centers. Please contact us using the contact information listed at the bottom of this page.

Firmware changes:Firmware Version 1.1.1 incorporates the following enhancement:

1. Changes the control algorithm of the focus drive, and enhances the drive’s responsiveness for more precise focus and adjustments. In particular, the new firmware enhances the AI servo AF capability of the lenses to track objects that move irregularly in sports events, such as soccer or rugby.

Affected Products:Firmware Version 1.1.1 is for lenses with Firmware Version 1.0.0. If the lens’ firmware is already Version 1.1.1, it is not necessary to update the firmware. The serial numbers (10 digits) of the lenses equipped with Firmware Version 1.0.0 are as follows:

EF300mm f/2.8L IS II USM:The third digit in the serial number is either 0, 1, 2, or 3 (xx0xxxxxxx, xx1xxxxxxx, xx2xxxxxxx, xx3xxxxxxx).

EF400mm f/2.8L IS II USM:The third digit in the serial number is either 0, 1, 2, or 3 (xx0xxxxxxx, xx1xxxxxxx, xx2xxxxxxx, xx3xxxxxxx).

EF500mm f/4L IS II USMThe third digit in the serial number is 0 (xx0xxxxxxx).

EF600mm f/4L IS II USMThe third digit in the serial number is 0 (xx0xxxxxxx).

Lenses with serial numbers other than those listed above are equipped with Firmware Version 1.1.1 or later.

Good thing that Canon is doing this.On the other hand.....what is going on with the Quality Assurance at Canon?

I wouldn't necessarily call it a quality assurance issue. Canon has just developed a brand new 61pt AF system and drive in their new pro bodies that has some advanced capabilities not previously used. Seeing as all of these lenses were designed and announced well before the 1D X was even announced, let alone released, its not surprising they have an update to these lenses that would fully support their new AF system.

I wouldn't necessarily call it a quality assurance issue. Canon has just developed a brand new 61pt AF system and drive in their new pro bodies that has some advanced capabilities not previously used. Seeing as all of these lenses were designed and announced well before the 1D X was even announced, let alone released, its not surprising they have an update to these lenses that would fully support their new AF system.

+1. At least Canon is willing to update/fix these issues when new technologies/products are introduced. 3rd party manufactuers can also run into these issues as well, but how often would they acknowledge and fix the issue?

Good thing that Canon is doing this.On the other hand.....what is going on with the Quality Assurance at Canon?

I wouldn't necessarily call it a quality assurance issue. Canon has just developed a brand new 61pt AF system and drive in their new pro bodies that has some advanced capabilities not previously used. Seeing as all of these lenses were designed and announced well before the 1D X was even announced, let alone released, its not surprising they have an update to these lenses that would fully support their new AF system.

This firmware update will be performed by Canon Service Centers. Please contact us using the contact information listed at the bottom of this page.

I would assume they have a special lens mount on a special device that attaches to a computer or other firmware update system. Mount the lens to such a thing, and it could be updated through its standard contacts that drive IS, AF, and allow the camera to control the aperture.